The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1981
Filed:
Jul. 05, 1979
Fritz Graser, Ludwigshafen, DE;
Paul Guenthert, Schifferstadt, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A process for converting a crude, coarsely crystalline perylene-3,4,9,10-tetracarboxylic acid diimide of the formula ##STR1## where A is unsubstituted or substituted phenyl, an unsaturated 5-membered or 6-membered heterocyclic ring which contains one or two nitrogen atoms and may be fused to a benzene nucleus, C.sub.3 -C.sub.6 -alkyl, or C.sub.2 -C.sub.3 -alkyl which is substituted by C.sub.1 -C.sub.4 -alkoxy, phenyl or C-acylamino, to a pigmentary form, wherein the crude pigment, in aqueous suspension, is comminuted in a high-speed mill in the absence of a surfactant. The pigments obtained give pure shade colorations of high to extremely high hiding power, and have a high tinctorial strength in white reductions.